A preparative column chromatographic method for isolation of carotenoids and chlorophylls from Gynostemma pentaphyllum, a traditional Chinese herb, was developed to evaluate their antiproliferative effects on the hepatoma cell Hep3B. An open column containing 70 g of magnesium oxide-diatomaceous earth (1:2.5, wt/wt) was used to elute carotenoid with 2% ethanol in ethyl acetate and chlorophyll with 50% ethanol in acetone. After high-performance liquid chromatography-mass spectrometry analysis, the carotenoid fraction was composed of all-trans- and cis-isomers of lutein, α-carotene, and β-carotene as well as epoxy-containing carotenoids, while the chlorophyll fraction consisted of chlorophylls a and b and their derivatives. Both carotenoid and chlorophyll fractions as well as lutein and chlorophyll a standards at 50-100 μg/mL were effective against Hep3B cells with a dose-dependent response with the following order: carotenoid fraction > chlorophyll fraction > lutein > chlorophyll a. For all treatments, the cell cycle was arrested in the G₀/G₁ phase, with Hep3B cells undergoing necrosis or apoptosis.